To test stuff you can make another account and do a pre-arranged game against that "friend".
Just in case some strange interaction happens and you want to replicate it, thats probably among the easiest ways.
The MTG-Arena UI could for sure need some more pointers to what cards an effect corresponds to and what "target" it has.
They do a somewhat reasonable job for targeting spells in that regard.
But for more complicated cards that target effects and triggers instead of cards, they currently have no representation to click on as they are no cards and for these choices they build all these extra UIs with buttons and boxes.